14 Design of Pile cap

Sl No Load combination p/n Tonsload due

to ML(T/m)load due to

MT (T/m)p/n

Tons

load due to

ML(T/m)

load due to MT (T/m)

P1 Tons

P2 Tons

P3 Tons

P4 Tons

P5 Tons

P6 Tons

Total load

P1+P3+P5

Tons

P2+P1 Tons

P2+P4+P6

Tons

P3+P4 Tons Shear

BM @ section

AA

BM @ section

BB

1 Group I (Case-1) 192 33 130 192 33 130 95 355 29 289 62 322 1151 185 450 965 317 185 628 1102

2 Group I (Case-2) 186 33 131 186 33 131 89 350 22 284 56 317 1119 167 439 952 307 167 619 1075

3 Group I (Case-3) 186 33 131 186 33 131 89 350 22 284 56 317 1119 167 439 952 307 167 619 1076

4 Group II(Case-1) Wind Load 180 34 156 180 34 156 58 371 -10 303 24 337 1082 72 428 1010 293 72 657 1050

5 Group II(Case-2) Wind Load 176 34 157 176 34 157 53 367 -14 299 19 333 1058 58 420 1000 285 58 650 1030

6 Group II(Case-3) Wind Load 176 34 157 176 34 157 53 367 -14 299 19 333 1058 58 420 1000 285 58 650 1030

7 Group III (Case-1) Seismic Transverse -ve169 1 106 169 1 106 64 276 62 273 63 274 1012 188 339 823 335 188 535 832

8 Group III (Case-2) Seismic Transverse -ve168 1 105 168 1 105 64 275 62 273 63 274 1011 190 339 821 335 190 534 831

9 Group III (Case-3) Seismic Transverse -ve168 1 105 168 1 105 64 275 62 273 63 274 1011 190 339 821 335 190 534 831

10 Group III (Case-1) Seismic Transverse +ve175 1 106 175 1 106 70 282 68 279 69 280 1048 206 351 841 347 206 547 861

11 Group III (Case-2) Seismic Transverse +ve174 1 105 174 1 105 70 281 68 279 69 280 1047 208 351 839 347 208 545 860

12 Group III (Case-3) Seismic Transverse +ve174 1 105 174 1 105 70 281 68 279 69 280 1047 208 351 839 347 208 545 860

13 Group IV (Case-1) Seismic vertical -ve 162 1 59 162 1 59 103 222 101 220 102 221 970 307 325 663 321 307 431 79714 Group IV (Case-2) Seismic vertical -ve 162 1 59 162 1 59 103 222 101 220 102 221 969 307 325 662 321 307 430 797

15 Group IV(Case-3) Seismic vertical -ve 181 1 59 181 1 59 123 242 121 239 122 241 1088 367 365 722 361 367 469 894

16 Group IV (Case-1) Seismic vertical +ve 182 1 59 182 1 59 123 242 121 240 122 241 1089 367 365 723 361 367 470 89517 Group IV (Case-2) Seismic vertical +ve 181 1 59 181 1 59 123 242 121 239 122 241 1088 367 365 722 361 367 469 894

18 Group IV (Case-3) Seismic vertical +ve 181 1 59 181 1 59 123 242 121 239 122 241 1088 367 365 722 361 367 469 894

19 Group V (Case-1) accidental longitudinal 141 12 47 141 12 47 106 200 82 175 94 188 844 281 306 563 257 281 366 749

20 Group V (Case-2) accidental longitudinal 138 12 47 138 12 47 103 197 78 173 91 185 828 272 300 556 252 272 361 736

21 Group V (Case-3) accidental longitudinal138 12 47 138 12 47 103 197 78 173 91 185 828 272 300 556 252 272 361 736

22 Group V (Case-1) accidental transverse 141 12 47 141 12 47 106 200 81 175 94 188 844 281 306 563 257 281 366 74923 Group V (Case-2) accidental transverse 138 12 47 138 12 47 103 197 78 173 91 185 828 272 300 556 252 272 361 736

24 Group V (Case-3) accidental transverse 138 12 47 138 12 47 103 197 78 173 91 185 828 272 300 556 252 272 361 736

Design parameters: 5.30

A

0.85

MT

B ML 8.90

3.6 3.6

14.1 Section AA - Design Parameters A

width of pilecap along traffic direction b = 8900 mm

width of pilecap across traffic direction b = 5300 mm

Depth of the section D = 1800 mm

Effective depth of the section d = 1672 mm

Clear cover = 75 mm

Cover to the main reinforcement cs = 128.5 mm

Characteristic concrete compression strength fck = 35 MPa

Characteristic concrete tensile strength fctm = 2.80 MPa

Characteristic reinforcement yield strength fyk = 500 MPa

Partial safety factor for Concrete c = 1.50

Partial safety factor for steel s = 1.15

Design reinforcement yield strength fyd = 434.78 MPa

Design concrete compression strength fcd = 15.63 MPa

For rectangular sress block,

= 0.8 for fck till 60MPa

= 1 till 60Mpa

= 0.4 rectangular stress block considered

fav = 12.51 MPa

Lever arm about 'A-A' (for piles 2,6,4) = 0.65 m

Lever arm about 'A-A' (for piles 1,5,3) = 0.65 m

Counteracting Bending Moment due to selfwt about section AA = 450.56 kNm =(8900/1000)(1800/1000)((5300/1000-2.30)/2)^21/225.0

Maximum Moment about Section AA M = 6115 kNm

A

A

B

Diameter of bars = 25 mm

Number of bars in section ns = 58 Nos

C/C Spacing of bars as = 151.6 mm =(8900-275-216-225-25)/(58-1)

Diameter of stirrups = 16 mm

Reinforcement area provided As = 28470.7 mm2

Kav considering fav = 0.01966

The actural deg of reinforcement specified, = 0.0532 < wbal 0.8

< wmax 12.24

> wmin 0.040

Results

Reinforcement area = 28470.7 mm2

The deg of reinforcement required , w or x/d = 0.0198

Thus, x = 33.128 mm

Lever arm z = 1658.249 mm

check limit to ensure yielding in reinforcement = 0.6168582 > 0.01982 OK

Reinforcement area required for developed moment

Ast req = 8481.2742 mm2 < 28470.7 mm2 OK

Reinforcement at top

Dia of bar = 16 Min reinforcement at section 19224 mm2

No of bars provided = 58 Min reinforcement required on top 9612 mm2

Total area of reinforcement provided = 11661.59 mm2

OK

Spacing of the bars = 152.1 mm

14.2 Section BB - Design Parameters

Breadth of the section b = 5300 mm

Depth of section D = 1800 mm

Effective depth of the section d = 1696.5 mm

Clear Cover = 75 mm

Cover to the main reinforcement cs = 103.5 mm

Characteristic concrete compression strength fck = 35 MPa

Characteristic concrete tensile strength fctm = 2.80 MPa

Characteristic reinforcement yield strength fyk = 500 MPa

Partial safety factor for Concrete c = 1.5

Partial safety factor for steel s = 1.15

Design reinforcement yield strength fyd = 434.78 MPa

Design concrete compression strength fcd = 15.63 MPa

For rectangular sress block,

= 0.8 for fck till 60MPa

= 1 till 60Mpa

= 0.4 rectangular stress block considered

fav = 12.51 MPa

Lever arm about 'B-B' = 2.45 m

Counteracting Bending Moment due to selfwt about section BB = 1298.63 kNm =(5300/1000)(1800/1000)((8900/1000-2.30)/2)^21/225.0

Maximum Moment about Section BB M = 9717 KNm

Diameter of bars = 25 mm

Number of bars in section ns = 58

C/C Spacing of bars as = 88.5 mm =(5300-275-216-225-25)/(58-1)

Diameter of stirrups = 16 mm

Reinforcement area provided As = 28470.7 mm2

Kav considering fav = 0.05093

The actural deg of reinforcement specified, = 0.0881 < wbal 0.8

< wmax 12.24

> wmin 0.040

Results

Reinforcement area = 28470.7 mm2

The deg of reinforcement required , or x/d = 0.052

x = 88.241 mmLever arm z = 1661.203 mm2

Check limit to ensure yielding in reinforcement = 0.6168582 > 0.05201 OK

Reinforcement area required for developed moment Ast req = 13452.94 mm

2 < 28470.7 mm2 OK

Reinforcement at topDia of bar = 16 Min reinforcement at section 11448 mm2

No of bars provided = 58 Min reinforcement required on top 5724 mm2Total area of reinforcement provided = 11661.59 mm2 OKSpacing of the bars = 88.9 mm

pile cap design-ULS